Detecting contamination in food production is vital to safety and quality control. Major brands, including chicken or snack food producers, have faced safety recalls in the last year due to possible metal contamination from their production processes. These recalls are hugely disruptive, eat into profits, and may deter future customers.
The industry relies on two main inspection technologies: x-rays and metal detectors. Both are powerful tools, but each is best suited to certain use cases. For example, metal detectors may not effectively detect metal contamination in convenience foods packaged in foil trays.
Choosing the right metal contamination device is essential to producing unadulterated products that are safe for consumers and compliant with FDA regulations. In some situations, it might be best to use both technologies to inspect food products comprehensively.
Food production professionals should understand the differences between each system and their ideal uses for unmatched food safety.
Major Differences and Purpose for Each Technology
When examining x-ray machines vs. metal detectors, their different detection capabilities and functionality are critical.
Detection Capabilities
Metal detectors can detect specific kinds of metal very well because of their magnetic properties. These ferrous metals include steel and iron. Non-ferrous metals like copper, aluminum, and brass are harder to detect.
Stainless steel is a ferrous alloy, which makes it difficult to detect because of its lower magnetic permeability.
For production facilities that rely on equipment made of non-ferrous metals, including stainless steel, it may be wise to include x-ray inspections in quality control procedures.
X-ray systems can detect a wide range of non-metal contaminants, including glass, stone, some plastics, and calcified bone pieces. They can also detect product defects such as missing or broken products and underfilled packages. These systems offer advanced screening for industries prone to packaging issues and physical contaminants.
Packaging Compatibility
Metal detectors may not be compatible with all packaging types, including complex metalized packaging that can cause inaccurate readings. X-rays offer an advantage for convenience foods and snack packaging because foil linings do not disrupt them.
“Product Effect” Considerations
Certain food contents, including high moisture, salt, and fat levels, can negatively impact the accuracy of metal detectors. These product effects make x-ray systems a more reliable choice for foods that might impact readings, such as certain meats or dairy products.
Additional Inspection Functions
X-ray systems offer a wider range of inspection functions than metal detectors. While a metal detector solely focuses on detecting metallic physical contaminants, an x-ray inspects the item for contamination, fill level, missing components, and proper seals.
How X-Ray Inspection Works
In comparing x-ray machines vs. metal detectors, it is important to understand the process of x-ray inspections.
Core Technology Principles
X-rays use electromagnetic radiation to detect physical contaminants through density differentiation. The x-rays pass through less dense materials easily, while more dense materials absorb more of them and will appear darker in the image. In food preparation, these detection mechanisms highlight contaminants such as metal, bone, dense plastic, and other dense materials.
Typically, x-ray systems are paired with data processing and analysis systems to collect information on rejected products for audits.
Key Components of an X-Ray System
X-ray systems rely on power sources such as generators, which combine the x-ray tube with a high-voltage and filament power supply. These systems also contain multiple sensors, usually designed in a detection array for maximum inspection coverage. Image processing software is built in to analyze the scan for contaminants and inform the rejection process. Some of the most common rejection mechanisms include air shots and pushers.
Safety Considerations
Operators should be aware of a few safety considerations for x-ray systems. First, they should take preventative measures to protect themselves from overexposure to ionizing radiation by standing behind shields or wearing lead aprons and gloves. It is also vital that sites train operators to understand the beam positioning to minimize their radiation exposure.
X-ray systems contain built-in safeguards and monitoring systems to protect operators, including excess radiation detection and automatic shut-offs when improper use is detected.
According to radiation experts and the FDA, the impact of radiation on food in industrial settings is thought to be nearly nonexistent.
How Metal Detection Works
It is important to understand how metal detectors work in food production contexts when evaluating x-ray machines vs. metal detectors.
Core Technology Principles
Unlike an x-ray, a metal detector does not rely on radiation. Instead, these systems create electromagnetic fields and rely on the differences in magnetic permeability across substances to reveal contamination. These machines use a three-coil system, which features one transmitter coil that generates electromagnetism and two receiver coils that detect disruptions in the field caused by contaminants.
Metal detectors rely on signal processing to determine which disruptions to the field are “white noise” and which are metal. Once a product is flagged as contaminated, an AI or human analysis can double-check these interpretations.
Key Components of a Metal Detector
A metal detector consists of three transmitter and receiver coils and a series of electronic systems to process the images. It also includes aperture sizes tailored to the product dimensions and conveyors that provide smooth, sanitary transport of the product. The reject mechanisms used most often in metal detectors are similar to those used in x-rays, including airshows and pushers.
Advancements in Metal Detection Technology
Metal detection technology is evolving. Modern systems often use multi-coil designs for enhanced sensitivity and offer digital signal processing to filter noise and reduce false rejection rates. Some offer multi-frequency operation for more precise detection of concealed contaminants.
When To Use X-Ray Inspection
There are situations in food production that better suit x-rays over metal detectors.
Product Types Best Suited for X-Ray
Any product that uses metal or metalized packaging (such as aluminum-lined items) requires an x-ray to check for physical contaminants. Products with non-metal physical contaminants, such as bone or dense plastics, should also use x-ray detection.
Finally, when multiple quality checks are necessary, it is best to use an x-ray system, even if the item passes through a metal detector first.
Production Line Considerations
When deciding whether to implement an x-ray system into a production line, it is helpful to consider where to place it to limit speed interruptions and suit the available space. Typically, x-rays should act as an end-of-the-line quality control measure.
Bear in mind that these systems can be fairly large, so smaller sites may find them more difficult to implement.
Industry Applications
X-ray systems are helpful safety and quality control tools in many prepared food industries, including packaged goods and ready meals, canned products, and foil-wrapped items. These machines are also useful for detecting bones in meat and poultry.
When To Use Metal Detection
Certain industries may benefit from using metal detectors instead of x-ray machines.
Product Types Best Suited for Metal Detection
Metal detection is best for raw ingredients and bulk materials, especially those that are non-conductive (not high in moisture, salt, or fat) and may face metal contamination risks.
Production Line Considerations
Metal detectors can offer more versatility in high-speed production environments, especially as they can be combined with checkweighers to streamline quality control. These systems also adapt to various production conditions and can be wash-down rated. Food producers should choose a metal detector based on space constraints and consider installing slim-line search head models for smaller footprints.
Industry Applications
Metal detection can be used at the beginning of the production line to protect equipment or at the end to ensure food safety and quality control. These machines are especially useful in dry ingredients, bakery products, and vertical packaging systems.
When To Use Both Technologies
Sometimes, it is safest to use metal detectors and x-rays to optimize compliance with food safety regulations and quality control.
Complementary Inspection Strategies
Sequential inspection for contamination, underfill, and packaging defects offers multiple chances to catch issues before releasing a product. By combining metal detectors in the earlier stages of production with x-rays as an end-of-the-line measure, producers can reduce their risk and create redundancy for critical control points (CCPs).
Strategic Placement in Production Lines
Most producers use metal detection in the early stages of production to check raw materials for contamination, as this protects their equipment. X-rays are more useful at the end of production, right after processing, or during the final packaging checks.
Case Studies of Integrated Approaches
Comprehensive inspection systems should involve redundancy to prevent safety issues and potential product recalls. A system might start with passing raw materials through a metal detector and end with an x-ray inspection and a manual check of the final product.
Regulatory and Economic Considerations
Food producers considering implementing metal detectors or x-rays should consider the current food safety regulations. The cost of these systems is also an important factor in whether they are suitable for a given site.
Compliance Requirements
The HACCP manages food safety through assessments and interventions of potential hazards during food production. The FDA uses this management system to regulate every part of production, from raw materials to a product’s final packaging. X-rays and metal detectors can help food producers comply with the FDA’s low tolerance requirements for physical contaminants.
These machines also aid in meeting industry-specific regulations. For instance, dairy products have such a high moisture and fat content that they exhibit product effects, and x-rays are essential to foreign object detection.
The FDA also requires food producers to document their quality control checks and the results of any rejections, which is much easier with automated x-ray or metal detector systems.
Cost Analysis
X-rays typically require a higher initial investment, and their operational costs are higher due to increased energy and maintenance demands. Metal detectors may last longer and depreciate more slowly than x-rays.
However, x-rays boast more advanced detection abilities that may be worth it for many industries. The return on investment for these machines may be higher because they offer enhanced protection against recalls that negatively impact brand reputation.
Total Cost of Ownership
When comparing x-ray machines vs. metal detectors, the total cost of maintenance across an x-ray system’s shorter lifespan is higher. These systems also require specialized training for employees to curate operational expertise.
Implementation Best Practices
Several considerations apply to the implementation of either machine.
Risk Assessment Approach
Producers should identify CCPs in their production line and evaluate contamination risks to determine the appropriate technology and location.
Testing and Validation
Once the unit is in place, regular testing protocols are vital to maintaining proper detection limits (as regulated by the FDA). Operators should also establish consistent documentation practices to create an audit trail.
Integration With Quality Management Systems
Experts can assist food producers in integrating the new machines into existing quality management systems to streamline data collection and analysis. This improves traceability and protects brands while allowing for continuous improvements.
Future Trends in Food Inspection Technology
The realm of food inspection is constantly evolving, which may influence the evaluation of x-ray machines vs. metal detectors.
Advancements in X-Ray Technology
X-rays have recently seen innovation in the form of dual-energy systems that provide more detailed analysis. The software algorithms used for analysis are also improving. These machines will likely continue using less energy and producing less radiation overspills to improve safety and cost efficiency.
Innovations in Metal Detection
Metal detectors with multi-spectrum technology are becoming more common due to their versatility. These systems also feature enhanced digital signal processing that improves the user experience and accuracy of results. Some models are beginning to offer compensation for product effects.
Integrated and Intelligent Systems
Many metal detectors and x-ray systems are starting to include AI data analysis features that may enhance detailed screenings and reduce false rejections. Remote monitoring features also improve production flow and sometimes include predictive maintenance services.
Choose TDI Packsys
For the highest-quality metal detectors and x-rays in the food production industry, trust TDI Packsys. Our models provide exceptional accuracy, stability, and sensitivity. Investing in these machines improves your brand’s food safety compliance and quality control, helping prevent recalls. Our experienced team can help you compare x-ray machines vs. metal detectors and choose the right imaging technology for your brand.
